{
  "bibcode": "2018GCN.23426....1D",
  "body": "V. D���Elia (SSDC), A. Y. Lien (GSFC/UMBC), M. H. Siegel (PSU) report on behalf of the Swift team:\r\n\r\nWe performed further analysis of the Swift data of the BAT trigger 872470 (D���A�� et al. GCN Circ. 23425)\r\n\r\nThe ground analysis using the BAT data set from T-239 to T+963 sec shows nothing significant in the BAT light curves. Also, the BAT image significance decreases to ~ 1.4 sigma.\r\n\r\nThe Swift/XRT began settled observations of the field 1033 s after the BAT trigger. The total exposure time is 2.8 ks, and data are entirely in Photon Counting (PC) mode. No X-ray sources have been detected in the BAT error circle. The 3-sigma upper limit at the BAT position is 6E-3 cts/s corresponding to a 0.3-10 keV observed flux of 2e-13 erg cm^-2 s^-1 (assuming a typical GRB spectrum).\r\n\r\nThe Swift/UVOT began settled observations of the field 1074 s after the BAT trigger. No optical afterglow consistent with the BAT position is detected in the initial UVOT exposures to a limiting magnitude in the white filter of 20.4.\r\n\r\nWe thus conclude that this trigger was indeed due to particle background near the SAA and is not an astrophysical event\r\n\r\nThis circular is an official product of the Swift team.",
  "circularId": 23426,
  "createdOn": 1542643595000,
  "email": "valerio.delia@ssdc.asi.it",
  "subject": "Swift Trigger 872470: further Swift analysis",
  "submitter": "Valerio D'Elia at ASDC  <valerio.delia@ssdc.asi.it>"
}